Appendix II, #33
the Babcock-Wilcox, and the Herrtsdwf is a coil boiler with
f>ump circulation. (Saff. 918, 993,0;^ 1061.)
Plugs (see also p. 755). Fig. 802 is a section of
one of these as introduced by the National Boiler Insurance
Company. The white-metal should be renewed annually.
JP. 367. Modulus of Resilience,— -The greatest clastic
stress is often called jtrocf stress. Then, from diagram 2, Fig, 326,
we may define resilience as ( half proof load x proof strain,' or
The quantity /2~E is termed the modulus oj resiliency and
measures resistance to impact per cubic inch of the bar.
61 .—Compare the resilience per unit volume of two bolts
A arid B, In which for ^ Its length A has a sectional area *8 of the
remaining ft : and B has for & its length a sectional area 'B of the
remaining $j (Hons. Mach. Canst. Exam. i8«9i).
In each case let/"« unit stress on smaller area
and 'Sj « nnlt stress on larger area.
Also let a « larger area, an<l *S a » smaller area,
Then, talcing "bolt A, total resilience